YAVAPAI COUNTY, ARIZONA Federal Emergency ... - FEMA Region 9

Mapping, Inc. (Kenney Aerial Mapping, Inc., 1986), and the HEC-2 computer
data generated by AGK Engineers, Inc., were used to delineate the flood hazard
area presented in the study. Cross section data for the backwater analysis of West
Clear Creek were determined by obtaining digitized cross sections from Kenney
Aerial Mapping, Inc. (Kenny Aerial Mapping, Inc., 1986). The starting watersurface
elevation for West Clear Creek was adopted from the Verde River
floodplain information as included is the previous FIS for Yavapai County (U.S.
Department of Agriculture, 1964).
Cross-section data for the first restudy in the Town of Camp Verde were obtained
using digitized cross sections from Aerial Mapping Company, Inc. (Aerial
Mapping Company, Inc., Topographic Maps for Portions of Verde River, Scale
1:4,800, Contour Interval 4 feet, October 1993; Aerial Mapping Company, Inc.,
Topographic Maps for Lucky Canyon Wash and Copper Canyon Wash, Scale
1:2,400, Contour Interval 4 feet, October 1993; Aerial Mapping Company, Inc.,
Topographic Maps for Cherry Creek, Scale 1:4,800, Contour Interval 4 feet,
October 1993).
Data for the selected cross sections in the Town of Chino Valley for the HEC-2
model (USACE, November 1976) were taken directly from the topographic maps,
provided by Yavapai County. Bridge and culvert data were obtained from field
measurements.
Starting water-surface elevations for Santa Cruz Wash were developed using the
slope-area method.
A small area in the northwest portion of the Town of Chino Valley is affected by
flooding from Chino Valley Stream. The flood boundaries, base flood elevations
and floodway for Chino Valley Stream were taken from the analysis performed by
Henningson, Durham, & Richardson, Inc., for FEMA in 1981 and presented in the
Yavapai County Flood Insurance Study (U.S. Department of Agriculture, 1964).
In order to simulate the character of stream channels and their adjacent overbanks,
cross sections were compiled in the Town of Clarkdale, utilizing a topographic
map of the stream channels specified for study by detailed methods (Cooper
Aerial Surveys, Topographic Maps, Town of Clarkdale, Yavapai County,
Arizona, Scale 1:2,400, Contour Interval 2 feet, Tucson, Arizona, 1978).
Stream channel geometry used in the Town of Clarkdale floodplain analysis was
developed specifically for the FIS. Aerial photogrammetric methods were used to
compile topographic maps of the stream channel and adjacent floodplain areas for
developing the cross sectional geometry (Cooper Aerial Surveys, Topographic
Maps, Town of Clarkdale, Yavapai County, Arizona, Scale 1:2,400, Contour
Interval 2 feet, Tucson, Arizona, 1978). Stream channel geometry used in the
Town of Cottonwood floodplain analysis was developed specifically for the FIS.
Aerial photogrammetric methods were used to compile topographic mapping of
the stream channel and adjacent floodplain. These topographic maps were used to
develop the cross section geometry (Cooper Aerial Surveys, Topographic Maps,
Town of Cottonwood, Yavapai County, Arizona, Scale 1:2,400, Contour Interval
2 feet, Tucson, Arizona, 1978; Kenney Aerial Mapping, 1983, 1984). The
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